The present invention relates to a structure for reinforcing an automotive lid made of synthetic resin, and more particularly, relates to hood or trunk lid made of a synthetic resin having a particular arrangement of downwardly depending reinforcing ribs.
It is already known, as disclosed in Japanese Utility Model Publication No. 44-7602, Japanese Patent Application Laid Open No. 56-60776, or U.S. Pat. No. 4,353,857 to mold a reinforced cover member for an automobile for use such as a hood lid or a trunk lid from a synthetic reinforced resin. A cover member of this type generally has the advantage that it is lighter than one made of steel plate. However, it also has the disadvantage that it is generally inferior in rigidity. Therefore, in the prior art, the cover member is reinforced by forming a plurality of ribs projecting from the lower face of the lid body. Such reinforcing by the use of ribs is difficult to apply to a lid having a large area. If the number of ribs is increased to enhance the rigidity, the reinforcing effect is increased only a small amount relative to the rapidly increasing rate of the weight which would negate the benefit of using the reinforced synthetic over using metal. As an alternative, the height of the ribs can be increased, however, such an increase increases the vertical height of the cover member thereby reducing the volume available which is being covered.
The reduction of volume can particularly be a problem in certain areas of the engine compartment of an automobile. That is, it is well known that the engine or auxiliary equipment have local portions projecting upwardly from the main body of the engine. There arises a problem that the cover member or hood lid must accommodate these local projecting portions.